Initially, a spokesperson for the group, who scored two number one singles in the 90s with Keep on Movin' and We Will Rock You, a collaboration with Brian May and Roger Taylor from Queen, would perform as a duo.

But they later confirmed the act would not be performing at all.

Differences in political views of the group's members have come under the spotlight since the announcement.

Ritchie Neville has posted a number of Tweets which appear to show him leaning towards support for Brexit .

Meanwhile, Sean retweeted a message in support of EU migrants.

In a statement, 5ive told the Mirror: "When Rich and Scott agreed to play the event they understood that it was a pop concert funded by one of the Brexit organisations and not a political rally.

"As it has come to light that this is more a political rally with entertainment included they have both decided to cancel their involvement.

"They would like to make it clear that as a band Five have no political allegiances or opinions for either side. Their allegiance is first and foremost to their fans."

Ritchie Neville with ex-girlfriend Billie Piper (Image: Getty Images)

Sean Conlon appearing on the Voice in 2012 (Image: BBC)

The concert has been dogged by line-up changes, after previous headliners Sigma pulled out, saying they were not aware it was a pro- Brexit rally when they were booked.

A press release issued to coincide with the announcement of the concert read: "With surprise guest performers and speakers still to be announced during the build-up to the event, ‘bpopLIVE' is set to be the biggest political rally in modern British history."

Andy Wigmore, Head of Communications at Leave.EU, said: "We are delighted to be endorsing this event which we believe will be a fantastic finale to the referendum campaign."

The statement added: "This is a multi-artist show, line-up subject to change."